You might broaden your search a bit and include the Browning B-2000. It is a streamlined Auto-5, smoother and lighter. It is gas operated and has some real great features that make it an under-appreciated shotgun.
They were made from 1973-1980 and I had heard they were expensive to make and that’s what ended production. I don’t know if that is true, but they are a sweet semi auto..
Like the Double Auto, it was discontinued due to poor sales. Cost may have been a factor but it could have been ameliorated if sales would have been good. It was Browning's first attempt at a gas operated semiauto and it flopped. The side loading seemed to be the biggest turn off and it had pretty stiff competition from Remington's 1100 which had a chokehold on the market at the time.
I knew 3 people who had them, two were guides for geese. The guns seemed pretty reliable but the two guides traded them for Mossberg 835s as soon as they came out and the last on an 11-87 a couple years after that model came out. I might be tempted to buy one if the price was right but it would have to be "throw away" cheap as parts may be difficult to find. It is not a gun I would want as my only for this reason.
I would take the B-2000 over either version of the A-500, now those were losers!!
